<!DOCTYPE html>  
<html>  
  <head>  
    <title>Demo 13</title>
    <style>
div{  
    background-color: #b0d4de;
}
div.op {
    opacity: 0.4;
}
div.vb0 {  
    visibility: visible;
}
div.vb1 {  
    visibility: hidden;
} 
</style>  
  </head>  
  <body>  
    <div>Paragraph</div>
    <div class="op">Paragraph</div>
    <div class="vb0">Paragraph</div>
    <div class="vb1">Paragraph</div>
    <div>Paragraph</div>    
  </body>
</html>